Study Of The Lateral Deformation Of Pile Subjected To Side Load In Soft Soil Area

In the construction of Expressway in soft soil area,the near loading of pile foundation often results in lateral displacement of overlying soil,resulting in horizontal deflection of nearby pile foundation,leading to damage to the structure of the superstructure,and even lead to accidents.The paper takes the Shenzhen airport soil transportation pavement project as the background?The phenomena of lateral displacement and even flow around the pile due to near loading have been studied and analyzed,and good theoretical significance and engineering application value have been obtained.The related contents are as follows:First,this paper puts forward the method of pile-soil relative displacement model and m value method together(called p-d-m method in this paper).At the same time considering the soil as ideal elastic plastic materials,this paper introduces active and passive side ultimate earth pressure of pile.This method is more suitable to solve the lateral soil large deformation.In this method,using the finite difference method to get elastic-plastic solution,further,the corresponding MATLAB program is compiled and verified by a literature example.The theoretical values are in good agreement with the experimental values.The reliability and effectiveness of the method are proved.Second,considering the advantages of the discrete element in simulating large deformation and damage,based on the particle flow theory and the PFC program,a passive pile model under the action of the flow soil is established.The phenomenon of soil around the pile is obvious,and the displacement,the moment and shear of pile body show a similar law in the process of soil flow: at the beginning of a soil pile compression stage,the load is small,the displacement and internal force changes little;compressed to a certain extent,displacement and internal forces began to increase rapidly;at the last stage,the pile body displacement and internal force has no change,and the pile-soil interaction is in a stable dynamic equilibrium.Comparing the PFC simulation value with the calculated value of the MATLAB program,the two are basically consistent,verifying the correctness of the results,and also reveal the mechanism and influence law of the pile-soil interaction.Third,by using the simplified theoretical analysis method,this paper analyzes the influence of the pavement load,the proportion coefficient of the horizontal resistance coefficient,the undrained strength,the slope of the load,the stiffness of the soil and the pile diameter on the lateral displacement of the pile.Last,this paper analyzes and summarizes the site conditions,hydrogeological conditions,material mechanics parameters,control standards and other calculation conditions of Shenzhen airport soil transportation pavement project.Then,the MATLAB program is compiled to simplify the analysis of subgrade reinforcement and non reinforcement,and compared with the actual monitoring results,proving the feasibility and applicability of the reinforcement scheme program.Finally consider the complexity of the actual working conditions of the project,using 3D finite element software MIDAS to simulate the whole process,for further study analysis.